Question

1. choose the best answer.

when the milky way and andromeda galaxies collide and merge into one galaxy, they might form a(n) ______ galaxy.
elliptical
irregular
cluster
spiral

1. choose the best answer.

a ______ star’s brightness increases up to 1,000 times or more after it has fused all its hydrogen into helium.
red giant
white dwarf
main sequence
supergiant

Explanation:

Question 16:

When spiral galaxies (Milky Way and Andromeda are spiral) collide, they often merge into an elliptical galaxy due to the disruption of spiral structures and redistribution of stars. Elliptical galaxies have a smooth, featureless appearance typical of merged spiral systems.

After a main - sequence star fuses all its hydrogen into helium, it expands and its brightness increases significantly (up to 1,000 times or more) as it becomes a red giant. Red giants are in the post - main - sequence phase where this brightness increase occurs.

Answer:

A. elliptical

Question 17: